1. Field of the Invention
This invention relates to a floating type magnetic head, and more particularly to a type thereof wherein the area of bonding glass exposed to the floating surface of the magnetic head is minimized.
2. Description of Prior Art
Heretofore, a floating type magnetic head has been constructed such that a slider groove 2 is formed at a central part of a slider 1 made of a nonmagnetic material such as ceramic, so that floating surfaces 3 and 4 are formed on both sides of the slider groove 2 as shown in FIG. 1. A core inserting groove 5 is formed in one of the floating surfaces 3 and 4 at an intermediate position, and a magnetic core 6 made of ferrite and the like provided with a track forming portion 6a at an end is inserted in the core inserting groove 5 to be bonded by bonding glass 7 as shown in FIG. 2. The track forming portion 6a is provided by subjecting two side surfaces of the end portion of the magnetic core 6 to machining. A cut-away portion 9 is formed on one side surface of the slider 1 for providing a coil winding space.
The floating surfaces 3 and 4 are lapped and polished into mirror surfaces. However, since the machinability of the slider 1, glass portion 7 and the ferrite core 6 exposed to these surfaces is different between each other, recesses 7a tend to be formed in the bonding glass portion 7.
When the floating type magnetic head is operated for recording and reproducing data in and out of a magnetic medium (not shown), the recording medium is rotated at a high speed to produce an air flow that causes the magnetic head to float with a slight distance maintained from the surface of the recording medium. In this case, since the conventional construction of the floating type magnetic head has recessed portions 7a, as described above, on the surfaces of the glass portions 7, a negative pressure is produced in the recessed portions 7a. The production of the negative pressure deteriorates the floating posture of the magnetic head, causing head-crush against the recording medium and inviting a disadvantage of damaging the recording medium. Furthermore, a transducing gap 8 provided in the magnetic core 6 is placed in the inserting groove 5 surrounded by the slider 1, and therefore the gap 8 cannot be observed from outside, such a feature rendering the control of the depth of the gap 8 to be extremely difficult.